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United States Patent |
5,769,284
|
Vargas
,   et al.
|
June 23, 1998
|
Self-adjusting pick-up tube assembly for aspirating liquid from
containers
Abstract
A self-adjusting pick-up tube assembly for aspirating liquid from
containers of varying heights. Such assembly comprises (a) a platform
member adapted to be positioned in contact with the bottom of a container
when the pick-up tube is being used to aspirate liquid from such
container; (b) a disk-shaped member adapted to be retained in a position
proximate the container's liquid filling aperture when the pick-up tube is
in use; (c) a flexible conduit interconnecting respective liquid
passageways in the platform and disk-shaped members, and (d) a telescopic
mount for enabling relative movement between the platform and disk-shaped
members to accommodate containers of different height.
Inventors:
|
Vargas; Santos E. (Miami Lakes, FL);
Wollitzer; Thomas (North Miami Beach, FL)
|
Assignee:
|
Coulter International Corp. (Miami, FL)
|
Appl. No.:
|
623473 |
Filed:
|
March 28, 1996 |
Current U.S. Class: |
222/464.4; 222/464.6 |
Intern'l Class: |
B67D 005/60 |
Field of Search: |
222/464.4,464.6,464.5
|
References Cited
U.S. Patent Documents
558131 | Apr., 1896 | Warren | 222/464.
|
4273272 | Jun., 1981 | Blanc | 222/464.
|
5195664 | Mar., 1993 | Rhea | 222/464.
|
Foreign Patent Documents |
2 031 526 | Apr., 1980 | GB | 222/464.
|
Primary Examiner: Huson; Gregory L.
Attorney, Agent or Firm: Kurz; Warren W.
Claims
What is claimed is:
1. A pick-up tube assembly for aspirating a liquid from a liquid-containing
container having a filling aperture in a wall thereof, said assembly
comprising:
(a) a platform member adapted to be positioned in contact with the bottom
of a container at a location substantially opposite the container's liquid
access opening when the pick-up tube is being used to aspirate liquid from
such container, such platform having a liquid passageway extending between
a pair of surfaces thereof;
(b) a disk-shaped member having opposing surfaces and means defining a
liquid passageway between such surfaces, such disk-shaped member being
adapted to be retained in a position proximate the container's liquid
access opening when the pick-up tube is in use;
(c) a flexible conduit interconnecting the respective liquid passageways in
the platform and disk-shaped members, such flexible conduit being capable
of conducting liquid from the container; and
(d) mounting means for movably mounting the platform member for movement
relative to said disk-shaped member to enable said platform member to move
towards and away from said disk-shaped member.
2. The invention as defined by claim 1 wherein said mounting means
comprises a telescoping arrangement including a first and second rigid
tubes of different diameter, one tube having an end rigidly connected to
said platform member, and the other tube having an end rigidly connected
to said disk-shaped member, said tubes extending toward each other and
being concentrically arranged with respect to each other, whereby one tube
slides within the other as said platform and disk-shaped member are moved
toward and away from each other.
3. The apparatus as defined by claim 1 wherein said flexible tube has a
substantially rectilinear shape when no external forces are applied
thereto, and wherein said biasing function is provided by a restoring
force in said flexible tube tending to restore said flexible tube to a
rectilinear shape whenever an external force causes said flexible tube to
flex to a non-rectilinear shape.
4. The apparatus as defined by claim 1 wherein said platform comprises top
and bottom surfaces which are spaced apart and interconnected by an
endless surface therebetween, and wherein said passageway extends between
said top and bottom surfaces.
5. The apparatus as defined by claim 4 wherein one end of the liquid
passageway in said platform is disposed within a slot formed in the bottom
surface of said platform, whereby liquid may flow unimpeded by said
platform from the bottom of said container into the liquid passageway of
said platform.
6. The apparatus as defined by claim 1 wherein said platform comprises top
and bottom surfaces which are spaced apart and interconnected by an
endless surface therebetween, and wherein said passageway extends between
said top and endless surfaces.
7. The apparatus as defined by claim 1 wherein said platform comprises a
material having a density less than the density of liquid in said
container, and wherein the upper surface of said platform defines a
chamber into which liquid in said container may flow when said tube is in
use, the weight of such liquid contained by said chamber acting to further
bias said platform and disk-shaped members apart so that said platform
tends to remain in contact with the container's bottom.
8. The apparatus as defined by claim 1 wherein said disk-shaped member is
provided with a second aperture for admitting air into said container.
9. The apparatus as defined by claim 2 wherein said disk-shaped member is
provided with second aperture for admitting air into said container, and
wherein said second aperture is surrounded by one of said rigid tubes
comprising said telescoping arrangement.
10. The apparatus as defined by claim 1 further comprising a tubular member
communicating with the liquid passageway in the disk-shaped member and
extending outwardly from one surface of the disk-shaped member, such
tubular member being adapted to be connected to a source of negative
pressure when said tube is in use.
11. The apparatus as defined by claim 1 wherein said flexible conduit
comprises an endless wall defining a bellows structure by which the length
of said conduit can be varied by applying a longitudinal force parallel to
the longitudinal axis of said conduit.
12. The apparatus as defined by claim 1 wherein said flexible conduit
comprises a material selected from the group consisting of silicone,
polyurethane, rubber and thermoplastic elastomer.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to improvements in apparatus for aspirating
liquid from containers. More particularly, it relates to improvements in
so-called "pick-up tubes" which are adapted to cooperate with a vacuum
source to aspirate the entire contents of a liquid-filled container
through the top of the container.
2. Discussion of the Prior Art
In many technical disciplines, it is desirable to aspirate liquid from a
container through the container's filling aperture, usually located at or
near the top of the container. As shown in FIG. 1, apparatus for
performing this task commonly comprises a pick-up tube assembly T which
can be releasably connected to a container C and coupled to a vacuum
source V. The pick-up tube assembly usually comprises an elongated and
rigid tube 10 (shown substantially enlarged for the sake of illustration)
and some screw-on mechanism 11 for rigidly coupling the tube to the
filling aperture A of the container. The tube length is fixed, being
selected to approximate the vertical distance D between the container's
filling aperture and its bottom B. A portion of the tube's upper end 10A
extends through a circular disk 14 which forms a part of the pick-up tube
assembly and serves to suitably position the pick-up tube in the
container's filling aperture. Disk 14 has a diameter which is slightly
greater than the diameter of the container's filling aperture, whereby the
disk may rest upon and be supported by the rim 16 of the filling aperture.
Disk 14 is usually clamped in place atop the filling aperture by a
threaded cap 18 which engages threads formed in the exterior of a short
tubular section 19 surrounding the filling aperture. The tube's upper end
10A is adapted to engage a flexible conduit 20 through which liquid in the
container can be aspirated by the vacuum source. Ideally, the length of
the rigid tube inside the container is selected so that the tube's lower
end 10B rests on the container bottom when disk 14 is clamped in place
atop the container by cap 18. As shown, a small notch 22 is often formed
in the bottom of the pick-up tube to enable liquid at the container bottom
to enter the tube.
From FIG. 1, it will be appreciated that the length of the pick-up tube
inside the container must vary to assure the complete emptying of
containers of different height. If the tube length is too short, the lower
end of the tube will not reach the container bottom, and the container
cannot be emptied; if the tube is too long, disk 14 cannot be properly
seated on and connected to the container top.
Heretofore, it has been common for either the container manufacturer or the
provider of the liquid sold in the container to incorporate a pick-up tube
having a length which is particularly adapted for use with the container
in which it is sold. This solution to the problem adds considerable cost
to the container and, accordingly, is to be avoided.
SUMMARY OF THE INVENTION
In view of the foregoing discussion, an object of this invention is to
provide a self-adjusting pick-up tube assembly of the above type which
capable of being used in a variety of containers of differing heights.
The above object is achieved by the provision of a self-adjusting pick-up
tube assembly in which the distance between the tube's top and bottom is
automatically varied to accommodate different container heights as the
assembly is mounted, in a conventional manner, to the filling aperture of
the container. According to a preferred embodiment of the invention, such
a pick-up tube assembly comprises:
(a) a platform member adapted to be positioned in contact with the bottom
of a container at a location substantially opposite the container's liquid
access opening when the pick-up tube is being used to aspirate liquid from
such container, such platform having a liquid passageway extending between
a pair of surfaces thereof,
(b) a disk-shaped member having opposing surfaces and means defining a
liquid passageway between such surfaces, such disk-shaped member being
adapted to be retained in a position proximate the container's liquid
filling aperture when the pick-up tube is in use;
(c) a flexible and resilient conduit interconnecting the respective liquid
passageways in the platform and disk-shaped members, such flexible conduit
being capable of conducting liquid from the container; and
(d) mounting means for movably mounting the platform and disk-shaped
members for relative movement toward and away from each other.
Preferably, the conduit is resilient, comprising rubber, silicone,
polyurethane, thermoplastic elastomer or the like, and the mounting means
comprises a telescoping arrangement including a first and second rigid
tubes of different diameter, one tube having an end rigidly connected to
the platform member, and the other tube having an end rigidly connected to
the disk-shaped member, such tubes extending toward each other and being
concentrically arranged with respect to each other, whereby one tube
slides within the other as the platform and disk-shaped member are moved
toward and away from each other. Means are provided for biasing the
platform and disk-shaped members apart, i.e., in directions away from each
other, whereby the platform member engages the container bottom while the
disk-shaped member is retained at a location proximate the container's
filling aperture.
The invention and its advantages will be better understood from the ensuing
detailed description of preferred embodiments, reference being made to the
accompanying drawings in which like reference characters denote like parts
.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a prior art pick-up tube assembly in cross-section;
FIG. 2 is a cross-sectional illustration of a pick-up tube assembly
structured in accordance with a preferred embodiment of the invention;
FIGS. 3A, 3B and 3C are top, bottom and side plan views, respectively, of
the platform member comprising the FIG. 2 apparatus;
FIG. 4 is a top plan view of the disk-shaped member of the FIG. 2
apparatus;
FIGS. 5A and 5B are side elevations showing the pick-up tube assembly of
FIG. 2 in its extreme positions;
FIG. 6 illustrates an alternative embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 2, a self-adjusting pick-up tube assembly 30,
structured in accordance with a preferred embodiment of the invention, is
shown as comprising a platform member 32, a disk-shaped member 34, a pair
of interconnecting flexible conduits 35, and movable mounting means 36 by
which the platform and disk-shaped members are mounted for relative
movement towards and away from each other. In use, platform member 34
rests upon the container bottom B, opposite the container's filling
aperture A, while the disk-shaped member rests upon the circular rim
surrounding the filling aperture and is clamped thereto by a threaded cap
18. The flexible conduits preferably comprise a resilient material, such
as rubber, silicone, polyurethane or some other thermoplastic elastomer.
Referring additionally to FIGS. 3A and 3B, platform member 32 defines a
pair of internal liquid passageways P1 and P2 through which liquid can be
drawn from the container. Passageway P1 communicates with an inlet 38
located in the base of a notch N formed in the platform's bottom surface,
and passageway P2 communicates with an inlet 40 formed in a side wall 32A
of the platform. As shown in FIG. 3C, the location of inlet 40 is slightly
above the base of notch N so that, as the container empties, air in the
container will be drawn through inlet 40 before it is through inlet 38,
thereby providing a means for sensing a low level (i.e. near empty)
condition. Each of the passageways P1 and P2 communicates with a short
tubular member 42 extending upwardly from the top surface of the platform
member, each of such members being adapted to receive one end of the
flexible conduits 35. As shown in FIG. 3A, the top surface of the platform
member defines a pair of hollow chambers 44 which fill with container
liquid as the platform is submerged in the container. The weight of the
liquid operates to weigh down the platform member, urging it into contact
with the container bottom. Optionally, metal weights W1 and W2 may be
incorporated in the platform to further assist in urging the platform to
the container bottom. Preferably, the platform and disk-shaped members are
made of plastic.
Referring additionally to FIG. 4, disk-shaped member 34 is provided with a
pair of liquid passageways P3 and P4 which extend between the opposing
surfaces of the disk. Tubular members 50 extend through each of such
passageways, one end of each member being adapted to receive and couple to
an end of the flexible conduit 35, and the opposite end being adapted to
receive and couple to an end of a conduit 15 to which a vacuum source is
applied to aspirate liquid from the container. Preferably, a small vent
hole 52 is formed at the center of the disk-shaped member to equalize the
pressure inside the container with that outside the container.
As noted above, an important feature of the pick-up tube assembly of the
invention resides in its ability to be used to empty containers of varying
height. This feature is provided by enabling platform member to
self-adjust its spacing from the disk-shaped member. Preferably, this
self-adjustment feature is provided by the telescopic arrangement shown in
FIGS. 2, 5A and 5B. More specifically, the platform member is provided
with a rigid rod 54 which extends upwardly from the central portion of the
top surface thereof and slides within a rigid tube 56 extending downwardly
from the bottom surface of the disk-shaped member. The flexible liquid
conduits 35, when extended to their maximum length, as shown in FIG. 5A,
prevent disengagement between the rod and tube. As members 32 and 34 move
towards each other, as occasioned by placing the tube assembly in a
container having a height shorter than the maximum allowed spacing between
member 32 and 34, the liquid conduits 35 flex, as shown in FIGS. 2 and 5B,
to accommodate the shorter spacing.
An alternative to the preferred embodiment discussed above is shown in FIG.
6. As illustrated, a self-adjusting pick-up tube may comprise a
bellows-style conduit 60 made of a flexible and resilient material, such
as rubber. The length of the conduit is adjustable by applying a
longitudinal force F, as may be produced by bonding weights 68 to the
platform member 62. As in the case of the assembly discussed above, the
conduit is attached to a disk-shaped member 64 adapted to be clamped to
the filling aperture of a liquid container.
While the invention has been described with reference to certain specific
embodiments, it will be appreciated that variations can be made without
departing from the spirit of the invention, and such variations are
intended to fall within the scope of the following claims. For example,
the pick-up tube assembly may have only one or a multitude of flexible
conduits for aspirating liquid from the container. In the case of multiple
conduits, the conduits may be of the same outside diameter or be of
different diameters to accommodate different size vacuum hoses.
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